FIELD OF THE INVENTION
[0001] The present invention relates to a clutch-type electrical driving device for a bicycle
and a clutch-type drive thereof, and more particularly to a driving device that enables
an electrical driving assembly and a pedal shaft driving assembly to respectively
perform one-way clutch.
BACKGROUND OF THE INVENTION
[0002] Bicycles have been widely applied in many leisure and sporting activities and are
one of many popular transport means for people in their daily lives. A bicycle rider
applies forces on two pedals to drive a chainwheel or a sprocket to rotate, which
in turn brings a rear wheel of the bicycle to rotate and provide a source of force
for moving the bicycle forward. However, a bicycle rider, particularly an aged, a
female or a child, might become exhaustive when riding uphill or riding for a long
distance. To overcome this problem, an electric bicycle or a power-aided bicycle has
been developed and introduced into market. With the electric bicycle, the rider may
select to drive the chainwheel via an electrical driving assembly instead of the pedals.
[0003] While the electric bicycle is convenient, the structural design is complicated and
it requires relatively high manufacturing cost. It is therefore a pity the electric
bicycle is not widely accepted among consumers due to its high selling price. Moreover,
the electrical driving assembly added to the bicycle is too heavy and occupies a considerable
space, giving the bicycle an increased overall weight and somewhat cumbersome appearance.
Another disadvantage in the currently available electric bicycle is that when the
electrical driving assembly drives the chainwheel to rotate and thereby moves the
bicycle forward, the rotating chainwheel would bring a pedal shaft assembly connected
thereto to rotate along with it, causing two pedals connected to two ends of the pedal
shaft assembly to rotate at the same time at high speed. Under this condition, the
rider just could not position his or her feet on the pedals and would dangerously
lose his or her balance on the bicycle to even cause an accident in a worse condition.
Therefore, the inventor develops a clutch-type electrical driving device for the electric
bicycle and a clutch-type drive thereof, in order to overcome the drawbacks existed
in conventional electric bicycles and to increase the applicability thereof.
GB-2050270 discloses an electric bicycle. One of the tubes of a bicycle frame opens into a crank-gear
box and is fitted with at least one electric motor. The motor has a shaft coaxial
to the tube in which it is housed. Reduction gearing driven by the motor shaft has
an output connected through the intermediary of a bevel gear to a shaft keyed on a
spindle driving plate of the crank-gear. Storage batteries are provided which ensure
a supply of current to the motor, the batteries being capable of connection both in
series and in parallel with the motor or motors under the action of a reversing switch.
A second switch is provided for ensuring the opening or closing of the battery circuit.
SUMMARY OF THE INVENTION
[0004] A primary object of the present invention is to provide a novel, non-obvious, and
industrially useful clutch-type electrical driving device for a bicycle and a clutch-type
drive thereof, so as to overcome the drawbacks as found in conventional electrical
driving devices for a bicycle.
[0005] To achieve the above and other objects, the clutch-type drive according to the present
invention includes a drive unit, a gear module, a shaft support, a pedal shaft, a
shaft sleeve, a transmission sprocket assembly, a first one-way bearing, and a second
one-way bearing.
[0006] The drive unit has a rotatable driving shaft, and the gear module is internally provided
with at least one reduction gear set and mounted on the rotatable driving shaft of
the drive unit. The gear module has an output shaft for outputting a rotating force,
and a first steering gear is mounted on the output shaft. The shaft support is fitted
around the first steering gear, and is provided on two opposite lateral end walls
with a first shaft hole and a second shaft hole. The pedal shaft is transversely and
rotatably extended through the shaft support with two ends projected from the first
and the second shaft hole. The shaft sleeve is correspondingly fitted around the pedal
shaft, and has an inner end extended into the shaft support via the second shaft hole,
and a second steering gear is mounted on the inner end of the shaft sleeve and is
correspondingly driven by the first steering gear to rotate. The transmission sprocket
assembly includes a plurality of adjacent sprockets, which are correspondingly fitted
around the shaft sleeve. The first one-way gear is correspondingly mounted on the
transmission sprocket assembly and connected to the shaft sleeve, and the second one-way
gear is correspondingly mounted on the transmission sprocket assembly and connected
to the pedal shaft.
[0007] In a preferred embodiment of the present invention, the drive unit is a vertical-shaft
motor; the gear module is a gear governor; an inner bearing connection element is
mounted on one of the sprockets; and an outer bearing connection element is mounted
to an outer side of the inner bearing connection element. The inner bearing connection
element defines an inner bearing hole, which is correspondingly fitted around an outer
end of the shaft sleeve; and the outer bearing connection element defines an outer
bearing hole, which is correspondingly fitted around the pedal shaft. The first one-way
bearing is fitted in the inner bearing hole, while the second one-way bearing is fitted
in the outer bearing hole.
[0008] The first one-way bearing has an inner ring and an outer ring, wherein the inner
ring is not rotatable along with the outer ring of the first one-way bearing in a
single rotating direction, but is rotatable along with the outer ring in an opposite
rotating direction; and the outer ring of the first one-way bearing is correspondingly
fitted in the inner bearing hole while the inner ring of the first one-way bearing
is correspondingly fitted around the shaft sleeve. The second one-way bearing has
an inner ring and an outer ring, wherein the inner ring is not rotatable along with
the outer ring of the second one-way bearing in a single rotating direction, but is
rotatable along with the outer ring in an opposite rotating direction; and the outer
ring of the second one-way bearing is correspondingly fitted in the outer bearing
hole while the inner ring of the second one-way bearing is correspondingly fitted
around the pedal shaft.
[0009] According to the clutch-type electrical driving device for a bicycle provided by
the present invention, a one-way bearing is provided between the sprockets and the
electrical driving assembly, while another one-way bearing is provided between the
sprockets and the pedal driving assembly. In this manner, a user may select to rotate
the sprockets by the electrical driving assembly, so as to drive the bicycle to move
forward without bringing the pedal assemblies to rotate. Therefore, it is possible
to protect the user against any danger when riding the bicycle because the pedal assemblies
would not rotate along with the sprockets that are driven by the electrical driving
assembly to rotate at high speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Fig. 1 is an external appearance view of a clutch-type electrical driving device
for bicycle according to a preferred embodiment of the present invention;
[0011] Fig. 2 is an exploded view of Fig. 1;
[0012] Fig. 3 is a top view of Fig. 1;
[0013] Fig. 4 is a cross-sectional external appearance view of Fig. 1; and
[0014] Fig. 5 is a side cross-sectional view of Fig. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present invention will now be described with a preferred embodiment thereof and
with reference to the accompanying drawings. It is understood the accompanying drawings
are illustrated only for assisting in describing the present invention and are not
necessarily in compliance with the exact or precise size proportion and part arrangement
of a real product manufactured through implementing the present invention. Therefore,
the size proportion and part arrangement shown in the accompanying drawings are not
intended to limit the present invention, which is intended to be limited only by the
appended claims.
[0016] Referring to Figs. 1 to 5, a clutch-type electrical driving device for a bicycle
according to a preferred embodiment of the present invention includes a support tube
10, a vertical-shaft motor 20, a gear governor 30, a shaft support 40, a pedal shaft
50, a shaft sleeve 60, a transmission sprocket assembly 70, a first one-way bearing
80, and a second one-way bearing 90.
[0017] The support tube 10 is a long hollow tube with an upper end thereof connected to
a saddle of the bicycle.
[0018] The vertical-shaft motor 20 is a power-driven motor having a long cylindrical configuration,
and is axially mounted inside the support tube 10. The vertical-shaft motor 20 has
a downward projected rotatable driving shaft 21.
[0019] The gear governor 30 is a speed reducer internally provided with at least one reduction
gear set, and is mounted on the rotatable driving shaft 21 of the vertical-shaft motor
20 to axially mount in the support tube 10. Through a gear ratio thereof, the reduction
gear set is able to regulate the rotatable driving shaft 21 to a reduced rotating
speed, which is then output via an output shaft 31 of the gear governor 30. Since
the setting of gear ratio is a known skill that has long been utilized in the gear
transmission field and can be easily employed or replaced by one of ordinary skill
in the art, and since the setting of gear ratio is not a subject matter of the present
invention, details about the gear ratio setting of the gear governor 30 are not discussed
herein. A first steering gear 32 is mounted on the output shaft 31, such that the
first steering gear 32 is connected to and retained to the output shaft 31 and accordingly,
driven by the output shaft 31 to rotate. Alternatively, the first steering gear 32
can be a sector gear.
[0020] The shaft support 40 is connected to a lower end of the support tube 10 to locate
around the first steering gear 32. The shaft support 40 is provided on a top wall
with a through hole 41, which communicates with an internal space of the support tube
10 to allow the first steering gear 32 to extend through the through hole 41. Further,
the shaft support 40 is also provided on two opposite lateral end walls with a first
shaft hole 42 and a second shaft hole 43.
[0021] The pedal shaft 50 is rotatably extended through the shaft support 40 with two opposite
ends of the pedal shaft 50 projected from the first and the second shaft hole 42,
43. At least one first bearing unit 1A is provided between the pedal shaft 50 and
the first shaft hole 42 to allow the pedal shaft 50 to smoothly rotate relative to
the first shaft hole 42. And, an end of the pedal shaft 50 projected from the first
shaft hole 42 is herein defined as a first end 51, which is fixedly connected to a
first pedal assembly 2A so as to rotate along with the first pedal assembly 2A. On
the other hand, another end of the pedal shaft 50 projected from the second shaft
hole 43 is herein defined as a second end 52, which is fixedly connected to a second
pedal assembly 2B so as to rotate along with the second pedal assembly 2B.
[0022] The shaft sleeve 60 is a long hollow tubular member rotatably fitted around the pedal
shaft 50 and is rotatably extended through the second shaft hole 43. At least one
second bearing unit 1B is provided between the pedal shaft 50 and the second shaft
hole 43. The shaft sleeve 60 has an inner end that extends through the second shaft
hole 43 into the shaft support 40. A second steering gear 61 in the form of a sector
gear is mounted on the inner end of the shaft sleeve 60 corresponding to the first
steering gear 32, and is in a position perpendicular to the first steering gear 32
as well as meshes with the first steering gear 32, so as to convert a force output
via the output shaft 31 of the vertical-shaft motor 30 into a horizontal rotating
force output.
[0023] The transmission sprocket assembly 70 includes a plurality of adjacent sprockets
71, which are mounted around the shaft sleeve 60. An inner bearing connection element
72 is mounted to one of the sprockets 71 and defines an inner bearing hole 721 for
correspondingly fitting around an outer end of the shaft sleeve 60. Further, an outer
bearing connection element 73 is fixedly mounted to an outer side of the inner bearing
connection element 72 and defines an outer bearing hole 731 for correspondingly fitting
around the pedal shaft 50.
[0024] The first one-way bearing 80 includes an inner ring and an outer ring. The inner
ring of the first one-way bearing 80 is not rotatable along with the outer ring in
a single rotating direction, but is rotatable along with the outer ring in an opposite
rotating direction. The outer ring of the first one-way bearing 80 is correspondingly
fitted in the inner bearing hole 721 while the inner ring of the first one-way bearing
80 is correspondingly fitted around the shaft sleeve 60. Therefore, the output shaft
31 in rotating would correspondingly drive the transmission sprocket assembly 70 to
rotate at the same time while the transmission sprocket assembly 70 in rotating does
not feed back to affect the output shaft 31.
[0025] The second one-way bearing 90 includes an inner ring and an outer ring. The inner
ring of the second one-way bearing 90 is not rotatable along with the outer ring in
a single rotating direction, but is rotatable along with the outer ring in an opposite
rotating direction. The outer ring of the second one-way bearing 90 is correspondingly
fitted in the outer bearing hole 731 while the inner ring of the second one-way bearing
90 is correspondingly fitted around the pedal shaft 50. Therefore, the pedal shaft
50 in rotating would correspondingly drive the transmission sprocket assembly 70 to
rotate at the same time while the transmission sprocket assembly 70 in rotating does
not feed back to affect the pedal shaft 50.
[0026] According to the clutch-type electrical driving device for a bicycle provided by
the present invention, a one-way bearing is provided between the sprockets 71 and
an electrical driving assembly, while another one-way bearing is provided between
the sprockets 71 and a pedal driving assembly. In this manner, a user may select to
rotate the sprockets 71 by the electrical driving assembly, so as to drive the bicycle
to move forward without bringing the pedal assemblies 2A, 2B to rotate. Therefore,
the user would be protected against any discomfort and danger when riding the bicycle
because the pedal assemblies 2A, 2B would not rotate along with the sprockets 71 that
are driven by the electrical driving assembly to rotate at high speed. On the other
hand, when the user selects to drive the sprockets 71 of the bicycle via the pedal
assemblies 2A, 2B, the sprockets 71 would not feed back to bring the output shaft
31 and other electrical driving components to rotate. This in turn reduces the rider's
burden in applying force to pedal and avoids the internal components of the electrical
driving device from unnecessary frictional loss. With these arrangements, the clutch-type
electrical driving device for a bicycle according to the present invention is superior
to the prior art due to its largely improved utility and safety in use.
[0027] The present invention has been described with a preferred embodiment thereof and
it is understood that many changes and modifications in the described embodiment can
be carried out without departing from the scope of the invention that can be limited
only by the appended claims.
1. A clutch-type drive, comprising:
a drive unit (20) having a rotatable driving shaft (21);
a gear module (30) being internally provided with at least one reduction gear set
and being mounted on the rotatable driving shaft (21) of the drive unit; the gear
module having an output shaft (31) for outputting a rotating force; and a first steering
gear (32) being mounted on the output shaft (31);
a shaft support (40) being fitted around the first steering gear (32);
a pedal shaft (50) being transversely and rotatably extended through the shaft support
(40);
a shaft sleeve (60) being correspondingly fitted around the pedal shaft (50), and
having an inner end extended into the shaft support (40); and a second steering gear
(61) being mounted on the inner end of the shaft sleeve (60) to be correspondingly
driven by the first steering gear (32) to rotate;
a transmission sprocket assembly (70) including a plurality of adjacent sprockets
(71), which are correspondingly fitted around the shaft sleeve (60);
characterised in that
a first-one-way bearing (80) is correspondingly mounted on the transmission sprocket
assembly (70) and connected to the shaft sleeve (60); and
a second one-way bearing (90) is correspondingly mounted on the transmission sprocket
assembly (70) and connected to the pedal shaft (50).
2. The clutch-type drive as claimed in claim 1, wherein the drive unit is a vertical-shaft
motor (20), and the gear module is a gear governor (30).
3. The clutch-type drive as claimed in claim 1. wherein the shaft support (40) is provided
on two opposite lateral end walls with a first shaft hole (42) and a second shaft
hole (43), and the pedal shaft (50) is transversely and rotatably extended through
the shaft support (40) with two opposite ends of the pedal shaft (50) projected from
the first and the second shaft hole (42, 43), and the inner end of the shaft sleeve
(60) is extended into the shaft support (40) via the second shaft hole (43).
4. The clutch-type drive as claimed in claim 1, further comprising an inner bearing connection
element (72) mounted on one of the sprockets (71) and an outer bearing connection
element (73) mounted to an outer side of the inner bearing connection element (72);
the inner bearing connection element (72) defining an inner bearing hole (721), which
is correspondingly fitted around an outer end of the shaft sleeve (60); the outer
bearing connection element (73) defining an outer bearing hole (731), which is correspondingly
fitted around the pedal shaft (50); the first one-way bearing (80) being fitted in
the inner bearing hole (721); and the second one-way bearing (90) being fitted in
the outer bearing hole (731).
5. The clutch-type drive as claimed in claim 4, wherein the first one-way bearing (80)
has an inner ring and an outer ring; the inner ring being not rotatable along with
the outer ring of the first one-way bearing (80) in a single rotating direction, but
being rotatable along with the outer ring in an opposite rotating direction; and the
outer ring of the first one-way bearing (80) being correspondingly fitted in the inner
bearing hole (721), while the inner ring of the first one-way bearing (80) being correspondingly
fitted around the shaft sleeve (60).
6. The clutch-type drive as claimed in claim 4, wherein the second one-way bearing (90)
has an inner ring and an outer ring; the inner ring being not rotatable along with
the outer ring of the second one-way bearing (90) in a single rotating direction,
but being rotatable along with the outer ring in an opposite rotating direction; and
the outer ring of the second one-way bearing (90) being correspondingly fitted in
the outer bearing hole (731) while the inner ring of the second one-way bearing (90)
being correspondingly fitted around the pedal shaft (50).
1. Ein Kupplungsantrieb, bestehend aus:
einem Antriebsaggregat (20) mit einer rotierbaren Antriebswelle (21);
einem Zahnradmodul (30), das inwendig aus mindestens einem Untersetzungsgetriebewerk
besteht und an der rotierbaren Antriebswelle (21) des Antriebsaggregats (20) montiert
ist; das Zahnradmodul (30) aus einer Abtriebswelle (31) zum Abtreiben einer Rotierkraft
besteht und ein erstes Lenkgetriebe (32) an dieser Abtriebswelle (31) montiert ist;
einem Wellenträger (40), der passend um das erste Lenkgetriebe (32) montiert ist;
einer Pedalwelle (50), die quer und rotierbar durch den Wellenträger (40) eingeschoben
ist;
einer Schafthülse (60), die jeweils passend um die Pedalwelle (50) montiert ist und
deren inneres Ende in den Wellenträger (40) ragt; einem zweiten Lenkgetriebe (61),
das am inneren Ende der Schafthülse (60) montiert ist, um jeweils mit dem ersten Lenkgetriebe
(32) zum Rotieren angetrieben zu werden;
einem Antriebskettenradaufbau (70) mit mehreren angrenzenden Kettenrädern (71), die
jeweils passend um die Schafthülse (60) montiert sind;
dadurch gekennzeichnet, dass
ein erstes Einweglager (80), das jeweils passend am Antriebskettenradaufbau (70) montiert
und an der Schafthülse (60) befestigt ist; und
ein zweites Einweglager (90), das jeweils passend am Antriebskettenradaufbau (70)
montiert und an der Pedalwelle (50) befestigt ist.
2. Der Kupplungsantrieb nach Anspruch 1, wobei das Antriebsaggregat (20) als einen Motor
mit senkrechter Welle und das Zahnradmodul (30) als einen Zahnradregler ausgeführt
sind.
3. Der Kupplungsantrieb nach Anspruch 1, wobei der Wellenträger (40) zwei einander gegenüber
gebildete seitliche Endwände mit einem ersten Wellenloch (42) und einem zweiten Wellenloch
(43) aufweist, wobei die Pedalwelle (50) quer und rotierbar durch den Wellenträger
(40) eingeschoben ist und die beiden einander gegenüber geformten Enden dieser Pedalwelle
(50) aus dem ersten und zweiten Wellenloch (42, 43) herausragen und das innere Ende
der Schafthülse (60) durch das zweite Wellenloch (43) in den Wellenträger (40) ragt.
4. Der Kupplungsantrieb nach Anspruch 1, weiter bestehend aus einem Verbindungselement
(72) des Innenlagers, das auf einem der Kettenräder (71) montiert ist, und aus einem
Verbindungselement (73) des Außenlagers, das an einer Außenseite des Verbindungselements
(72) des Innenlagers montiert ist; das Verbindungselement (72) des Innenlagers ein
Loch (721) durch das Innenlager aufweist, durch welches jeweils ein Außenende der
Schafthülse (60) ragt; das Verbindungselement (73) des Außenlagers ein Loch (731)
durch das Außenlager aufweist, durch das jeweils die Pedalwelle (50) ragt; das erste
Einweglager (80) passed in das Loch (721) des Innenlagers und das zweite Einweglager
(90) passend in das Loch (731) durch das Außenlager montiert sind.
5. Der Kupplungsantrieb nach Anspruch 4, wobei das erste Einweglager (80) einen Innenring
und einen Außenring aufweist; sich der Innenring dem Außenring des ersten Einweglagers
(80) in eine Drehrichtung entlang nicht rotieren läßt, jedoch zusammen mit dem Außenring
in eine entgegengesetzte Richtung rotieren läßt; der Außenring des ersten Einweglagers
(80) jeweils passend in das Loch (721) durch das Innenlager montiert ist, während
der Innenring des ersten Einweglagers (80) jeweils passend um die Schafthülse (60)
montiert ist.
6. Der Kupplungsantrieb nach Anspruch 4, wobei das zweite Einweglager (90) einen Innenring
und einen Außenring aufweist; sich der Innenring dem Außenring des zweiten Einweglagers
(90) in eine Drehrichtung entlang nicht rotieren läßt, jedoch zusammen mit dem Außenring
in eine entgegengesetzte Richtung rotieren läßt; der Außenring des zweiten Einweglagers
(90) jeweils passend in das Loch (731) durch das Außenlager montiert ist, während
der Innenring des zweiten Einweglagers (80) jeweils passend um die Pedalwelle (50)
montiert ist.
1. Un entraînement à embrayage, comprenant :
une unité d'entraînement (20) ayant un axe d'entraînement rotatif (21) ;
un module d'engrenage (30) étant muni intérieurement d'au moins un train d'engrenage
réducteur et étant monté sur l'axe d'entraînement rotatif (21) de l'unité d'entraînement
; le module d'engrenage ayant un axe de sortie (31) pour délivrer une force de rotation
; et un premier mécanisme de direction (32) étant monté sur l'axe de sortie (31) ;
un support d'axe (40) étant monté autour du premier mécanisme de direction (32) ;
un axe de pédale (50) est prolongé de façon transversale et rotative au travers du
support d'axe (40) ;
un manchon d'axe (60) étant monté de façon correspondante autour de l'axe de pédale
(50), et ayant une extrémité intérieure prolongée dans le support d'axe (40) ; et
un second mécanisme de direction (61) étant monté sur l'extrémité interne du manchon
d'axe (60) pour être entraîné de façon correspondante par le premier mécanisme de
direction (32) pour tourner;
un ensemble de pignons de transmission (70) comprenant une pluralité de pignons adjacents
(71), montés de façon correspondante autour du manchon d'axe (60) ;
caractérisé en ce que
un premier roulement unidirectionnel (80) est monté de façon correspondante sur l'ensemble
de pignons de transmission (70) et relié au manchon d'axe (60) ; et
un second roulement unidirectionnel (90) est monté de façon correspondante sur l'ensemble
de pignons de transmission (70) et relié à l'axe de pédale (50).
2. L'entraînement à embrayage selon la revendication 1, dans lequel l'unité d'entraînement
est un moteur à axe vertical (20), et le module d'engrenage est un engrenage régulateur
(30).
3. L'entraînement à embrayage selon la revendication 1, dans lequel le support d'axe
(40) est prévu sur deux parois d'extrémité latérales opposées avec un premier trou
d'axe (42) et un second trou d'axe (43), et l'axe de pédale (50) est prolongé de façon
transversale et rotative au travers du support d'axe (40) deux extrémités opposées
de l'axe de pédale (50) projetées à partir du premier et du second trou d'axe (42,
43), et l'extrémité interne du manchon de l'axe (60) est prolongée dans le support
d'axe (40) par l'intermédiaire du second trou d'axe (43).
4. L'entraînement à embrayage selon la revendication 1, comprenant en outre un élément
interne de connexion au roulement (72) monté sur l'un des pignons (71) et un élément
externe de connexion au roulement (73) monté sur un côté extérieur de l'élément interne
de connexion au roulement (72) ; l'élément interne de connexion au roulement (72)
définissant un trou interne de roulement (721), qui est monté de façon correspondante
autour d'une extrémité extérieure du manchon d'axe (60) ; l'élément externe de connexion
au roulement (73) définissant un trou externe de roulement (731), qui est monté de
façon correspondante autour de l'axe de pédale (50) ; le premier roulement unidirectionnel
(80) étant monté dans le trou interne de roulement (721) ; et le second roulement
unidirectionnel (90) étant monté dans le trou externe de roulement (731).
5. L'entraînement à embrayage selon la revendication 4, dans lequel le premier roulement
unidirectionnel (80) a une bague intérieure et une bague extérieure ; la bague intérieure
ne pouvant pas tourner avec la bague extérieure du premier roulement unidirectionnel
(80) dans un même sens de rotation, mais pouvant tourner avec la bague extérieure
dans un sens opposé de rotation ; et la bague extérieure du premier roulement unidirectionnel
(80) est montée de façon correspondante dans le trou interne de roulement (721), tandis
que la bague intérieure du premier roulement unidirectionnel (80) est montée de façon
correspondante autour du manchon de l'axe (60).
6. L'entraînement à embrayage selon la revendication 4, dans lequel le second roulement
unidirectionnel (90) a une bague intérieure et une bague extérieure ; la bague intérieure
ne pouvant pas tourner avec la bague extérieure du second roulement unidirectionnel
(90) dans un même sens de rotation, mais pouvant tourner avec la bague extérieure
dans un sens opposé de rotation ; et la bague extérieure du second roulement unidirectionnel
(90) est montée de façon correspondante dans le trou interne de roulement (731) tandis
que la bague intérieure du second roulement unidirectionnel (90) est montée de façon
correspondante autour de l'axe de pédale (50).